Ecogeographical Diversity and Dry Season Changes Along the Mainstream Mekong River in Thailand, Laos and Cambodia

The Mekong River is experiencing dramatic hydrological and sediment transport changes, largely due to the development of hydropower dams, both on its mainstream and tributaries. We ask, “how well do local people with a lifetime of experience living along and interacting with the Mekong River on a daily basis understand the changes that are occurring?” In this article, we present the results of research conducted with groups of villagers living in 44 communities located along the mainstream Mekong River from Chiang Saen District, Chiang Rai Province, in northern Thailand, downstream to Stung Treng Town in Stung Treng Province, northeastern Cambodia. Local people are well aware that changes are occurring and causing various types of negative environmental and social impacts, such as to seasonally inundated forests and vegetation along the river, sandbars, birds, algae, fish, mollusks, crabs and shrimps, semi-aquatic earthworms, and insects. Mitigation measures, such as the construction of river embankments, are causing their own adverse environmental impacts. Here, we argue that local knowledge related to the ecogeographical diversity of the Mekong River has been underappreciated, particularly as a result of increased reliance on remote sensing to understand environmental changes along the Mekong, and that local ecological knowledge can help us better understand Mekong River changes.